1. Field of the Invention
The present invention relates to a key operated lock that, while designed to accommodate special ignition switch needs of high quality motorcycles, also offers features that, taken alone or in combination, are well suited for use in other key operated lock applications. More particularly, the present invention relates to features of a key operated lock having a "hand positioned operator" or "knob" that is rotatable between or among a plurality of detented angular positions, wherein the knob has a tubular body that carries a lock mechanism having a barrel that journals a key-receiving plug for separate rotation between "locked" and "unlocked" positions when a properly configured key is inserted into the plug, with novel features including a unique way the knob and the lock mechanism are retained in a protective housing of the lock by utilizing a retaining bar that is closely received in a slip-fit within aligned, transversely extending slots formed in overlying side regions of the tubular body of the knob and the barrel of the lock mechanism, and unique ways: 1) of permitting the key to be inserted into and removed from the plug when the plug is in either of its "locked" and "unlocked" positions, but only when the knob is in its "off" position; 2) of permitting the knob to be rotated out of its "off" position but only when the key has been removed from the plug; and, 3) of providing a retractable bolt carried at the rear of the tubular body of the knob which extends to drivingly connect the knob to an electrical switch for operating the switch in response to rotation of the knob when the lock is "unlocked," and which retracts when the lock is "locked" to disconnect the knob from the switch.
2. Prior Art
Ignition locks for motorcycles and other engine powered equipment often are provided with a so-called "hand positioned operator" or "knob" that is rotatable between or among a plurality of detented angular positions to operate an electrical switch. When the lock is "unlocked" a driving connection is established between the knob and the electrical switch. When the lock is "locked" the knob is disabled from operating the switch. Ignition locks of this type typically permit their knobs to move between or among angular positions that are labeled "accessory on," "off" and "engine on"--or, more simply "ACC," "OFF" and "ON."
Some ignition locks of this type can be defeated by utilizing a wrench or other tool to force their knobs to rotate to "on" positions. To provide greater security, others of these ignition locks are provided with mechanisms for rendering their knobs "free wheeling" when the locks are locked so that rotation of their knobs between or among various angular positions will not cause operation of associated electrical switches.
In automobiles and trucks where little vibration of the ignition lock is likely to be encountered, it is accepted practice for the ignition key to remain in the key-receiving opening of the ignition lock while the vehicle is in operation. However, in motorcycles and other types of engine operated equipment where vibration of the ignition lock may be prevalent, it is desirable for the ignition key to be removed during vehicle operation so that the key will not vibrate out of the key-receiving opening and become lost. To ensure that the ignition key of a motorcycle is removed rather than left in place during operation of the motorcycle's engine, it has been proposed that the knob of the ignition lock be prevented from moving out of its "off" position unless and until the ignition key is withdrawn from the key-receiving opening.
One type of key operated lock mechanism that has received relatively little use in vehicle ignition locks is disclosed in U.S. Pat. No. 5,485,735 issued Jan. 23, 1996 to Timothy P. Laabs et al, and also in U.S. Pat. No. 5,531,084 issued Jul. 2, 1996 to Timothy P. Laabs et al (referred to hereinafter as the "Dimpled Key Lock Patents"), the disclosures of which are incorporated herein by reference. In accordance with the teachings of the Dimpled Key Lock Patents, two or more rows of spring projected tumblers having convexly rounded inner ends are received in dimple-like recess formations that are provided in at least two of the four side surfaces of a key of generally rectangular cross-section to enable a correctly dimpled key to operate a cam that is located at the rear of the lock mechanism. In preferred practice, the present invention makes use of selected features of key operated lock mechanisms of the type disclosed in the Dimpled Key Lock Patents.